Scores of trout die in Sheelin fish kill
WATCH: Film shows trout fish in distress at Captains Bay
Scores of trout have died in a fish kill at Lough Sheelin this week, according to local anglers.
The fish kill was detected on Wednesday, July 16 at an area known locally as 'Captains Bay' where Mountnugent River feeds into Sheelin.
The Lough Sheelin Trout Protection Association (LSTPA) said they are “extremely disappointed and concerned” by the development.
They estimate that “at least” 100 adult wild brown trout have died as a result of the incident some weigh up to 10lbs or 4.5kg.
"Those fish would be regarded as trophy fish by anglers all over the world," laments Eamonn Ross of LSTPA.
“The initial estimation of fish killed is probably an underestimation given the nature of the area and previous experiences of fish kills on the catchment.”
Inland Fisheries Ireland recovered 68 dead fish from the site; including 63 brown trout, two roach, one perch and two stone loach.
A video taken in the area shows trout displaying behaviour that suggests they are in distress.
“It's typical of fish who are having difficulty breathing,” Eamonn explains.
They describe Mountnugent River is “a critically important” spawning tributary for Lough Sheelin.
This week's Sheelin fish kill follows an incident in which a suspected pollution incident killed over 1,000 fish in a Ballinagh river.
LSTPA is eager to stress how they are not blaming anyone for the Sheelin incident. They recognise the recent warm weather poses a risk in relation to any increase in nutrient loading to the lake. However, likewise they insist this is not solely a “natural phenomenon” due to high temperatures.
“Something triggered increase in bio-oxygen demand (BOD) that resulted in less oxygen for the fish. We don't believe that's fully down to higher temperature, having said that we don't have any evidnec eof that other than we've seen high temperatures before and have never seen anything like this happening.
“The fact it happened at the mouth of the Mountnugent River would indicate to us that some increase in nutrient load triggered an increase demand for oxygen and that resulted in the fish kill.”
They have reported the incident to Inland Fisheries Ireland (IFI), who are conducting an investigation.
"Investigations thus far have not yielded any evidence of pollution," an IFI spokesperson told the Celt.
"IFI staff were on site late yesterday and early today, 17th July, to investigate the incident, which is believed to have been caused by prolonged recent hot weather.
"Monitoring and assessment of the lake and river will continue to be undertaken to identify the cause of the fish kill, and the quality of the water."
IFI suspects the event was caused by high water temperatures in combination with low dissolved oxygen levels, exacerbated by the presence of aquatic plant growth (which remove oxygen from the water at night during respiration), which impacts on larger fish disproportionately.
Necessary precautions
LSTPA note it takes very little increase in nutrient load to have a major impact on the lough given the current conditions.
“The LSTPA are asking that all necessary precautions are taken to ensure that waste disposal which could end up in rivers and lakes is avoided. This includes ensuring that all current regulations are monitored and policed.
“The LSTPA call on those responsible for ensuring safe and clean water in the Sheelin Catchment to take whatever measures are necessary including inspections and audits of all discharges to the Lake to ensure that incidents like this one are prevented from recurring.”
Eamonn urged members of the public to immediately report any incident of pollution or fish kill to Inland Fisheries Ireland, the relevant local authority and the Environmental Protection Agency.